The present invention relates generally to electrical pushbuttons and in particular, operators for pushbuttons that provide push-pull or twist-to-release modes of operation.
Electrical pushbuttons close or open electrical contacts in response to a pressing inward of a button or knob. Different pushbuttons may provide for different operating modes including: “momentary on”, where the knob returns by spring action after it has been released, “on-off” where alternate pressings of the knob activate and deactivate the contacts, “push-pull,” where pressing of the knob activates the contacts and the knob must be manually pulled to deactivate the contacts, and “twist to release,” where the knob remains in when pressed until it is twisted whereupon a spring causes the knob to return. Different pushbuttons may also provide for different electrical characteristics including different numbers of contacts and whether those contacts are normally open or normally closed.
For reasons of manufacturing efficiency and inventory management, it is known in the art to provide pushbuttons that may be assembled from modular contact blocks and operators. A contact block may include a normally open or normally closed contact and the operator may include the mechanism defining the operating mode of the pushbutton. Different operators may be assembled to one or more different or identical contact blocks to provide a wide variety of different types of pushbuttons.